In a famous story, a wise man in India requests a reward promised by his king. The wise man shows the king a chessboard having 64 squares. "Put 1 grain of rice on the 1st square, 2 grains on the 2nd square, 4 on the 3rd square, 8 on the 4th square, and so on. That will be my reward." The king readily agrees and is ruined because the total number of rice grains turns out to be about 37 trillion trillion trillion grains of rice - much more than the value of the entire kingdom. How many grains of rice go in the 14th square?

Respuesta :

8,192 because 
1 on 1
2 on 2
4 on 3
8 on 4 
16 on 5
32 on 6
64 on 7
128 on 8
256 on 9
512 on 10
1024 on 11
2048 on 12
4096 on 13
8192 on 14